US1870164A - Turbulent burner - Google Patents

Description

@mg E, 193Z- A. w. BENNis TURBULENT BURNER Filed March 29, 1929 2 Sheets-Sheet 2 Patented Aug. 2, 1932 UNIT-ED STATES PATENT FFQE TURBULEN T BURNER Application led March 29, 1929, Serial No.

T he present invention relates vto turbulent burners particularly for pulverulent fuels.

In the vknown types of turbulent burners the mixing of .the fineiy divided fuel and air has been accomplished by whirling about the fuel and the air either combined or separately, and either with a low or .a high velocity. The action therefore, has been chiefly whirling as distinct from a turbulent motion such asis caused when liquid is poured from a vessel into a tumbler or the like from a great height. Y

In these known types of burners, inclined vanes have been used to obtain the necessary r whirling efect, but it will be appreciated that greater mixing of the fuel and air is desired beyond that which can be accomplished by any whirling action. The greater the proportion of air which can be introduced into 1` the finely divided fuel and the more intimate the mixing between such air and the fuel, the more rapid and efficient will be the subsequent combustion. i

According to the present invention the streams of air and fuel are passed into the.

A direction is equal to 180.

Preferably the burner is provided with la base portion against which the fuel and air is projected and after turbulence has been set f up., the resultant mixture is project-ed through a suitable orifice into ythe furnace. VThe burner is preferably of a cup or tumbler-like forml the exit orifice of the burner being of any desired shape according to the desired shape of flame.

One or more annular or other orifices or channels may be provided around the burner through which additional hot or cold air re quired for combustion may be supplied. These annular orifices or channels around 350,984, and in Great Britain April 2, 1928.

the orifice of the burner may be adjustably controlled.

rEhe base of the burner may be adjusted from the outside of the furnace so as to alter the relationship ofthe fuel feeding oriices and the base thereby adjusting th-e tur-y bulent effect.

The invention is more particularly described with reference to the accompanying drawings in which z- Figure 1 shows in section one form of turbulent burner constructed according to the present invention.

Figure 2 is a cross sectional view of Figure 1 on the line 2, 2 of Figure. 1.

Figure 3 is a section of a modified form of construction.

Figure 4 is a cross sectional elevation along the line 6, 6 of Figure 3.

Figure 5 is a sectional view of another form of construction. y

Figure 6 is a cross sectional view thereof along the linevll, 11 of Figure 5. n

Figure 7 is a sectional elevation of a still further modified form of construction of burner.

In the drawings, which are pro-vided to illustrate certain examples of construction of the invention and are not intended to conne the invention Vto the examples illustrated, and with regard to Figures 1 and 2 in particular the burner is formed in three `portions 12, l'and 14 connected together by flanges, the inlet for the pulverulent fuel and air being indicated at l5 and being formed in the portion 12, whilst the portion 13 forms the body part of the burner and the portion 14 the mouth piece thereof. It will be understood that instead of airany suitable form of gas may be used, and this term is used solely as a descriptive term and not as a limiting term throughout the description and claims.

The base member of the burner is indicated at 16. This base member is mounted for longitudinal movement in the burner. A spindle 17 is rigidly connected to the base member and extends through the wall of the burner where it has a threaded connection withy the bracket so that when a suitable tool i :soL

is applied to the end 18 of the spindle, it may be turned for shifting the position of the base burner. By this means the position of the reaction plate or base member 16 of the burner may be shifted relative to the inner wali 19 forming the chamber of the burner.

The mixing chamber, within which turbulence of the combustible medium takes place, is provided with a number of inlet oriices 2O at the ends of inlet passages 21, these passages 21 communicating with a space 22 through passages 23 within which inclined or angled ribs or vanes 26 are formed. The inclined ribs or vanes 26 create a swirling or centrifugal effect on the air or gas and fuel passing through the duets 23.

The cross sectional area of the passages 21 slightly decreases from one end to the other in order to prevent trapping of the fuel and air or gas during their passage therethrough, this decrease of the cross sectional area being necessary in view of the fact that the inlet for the fuel and air from these passages into the chamber 24 of the burner is not at right angles to the direction of the passages.

It will be seen from this construct-ion that one inlet only is provided both for the supply of the fuel and air.

W'hen the air and fuel enter the burner through the orifice 15, a certain amount of initial turbulence is set up by reason of the projecting end 25 of the base member which lies in the path of the iow of the incoming air and fuel. The air and fuel then flow along passages 23 and 21 and the orifice 2O into the mixing chamber 24. By 4reason of the shape of the chamber 22 it is possible that a bigger proportion of fuel will be present in the medium passing along the lower passages 23 than along the higher passages 23 by 4reason of the action of the centrifugal force on the air and fuel, but this has no effect on the resultant mixture of fuel and air as the most efficient mixing takes place when the fuel and air enter the chamber 24 and impinges against the base plate 16 prior to its complete reversal of direction of travel outwardly through the mouth piece 14.

The burner shown in Figures 3 and l is basically the saine as shown in Figures 1 and 2,with certain added features of structure. In this construction an inlet 37 is provided for the primary air and fuel. whilst a separate inlet 38 is provided for the secondary air. The passage of the primary air and fuel along ducts 39 between a plurality of angled or inclined ribs or vanes 4() formed therein has a suction effect on the secondary air to cause this to enter the ducts 21 and from thence through the orifices 2O into the burner chamber 24. The primary air of course, is that volume of air suflicient to convey the powdered fuel into the burner chamber and is generally somewhere in the region of 30% of the total air supply.

In this case by reason of the suction effect of the primary air on the secondary air, the hot secondary air from the furnace can be used.

In this construction a modified piece 61 is provided within which propeller shaped blades or vanes are mounted on a shaft 64 which is supported within bearings 65 controlled by a remote control 66 situated externally of the burner.

The remaining details with regard to the construction of Figures 3 and 4 are similar to the construction described wit-h reference to Figures 1 and 2.

In Figures 5 and 6 of the drawings, a further modified form of burner is shown. In this form of the burner, the same basic principles of the burner illustrated in Figures 1 and 2 are used, with the added feature of the sleeve 55 which is disposed between the inner wall 19 of the burner and the base or reaction piece 16. The sleeve 55 is mounted so that it is shiftable. A tubular member 56 is connected to the sleeve and extends through the rear wall of the burner and has a threaded connection with a bracket, so that by turning the tubular member, the sleeve is adjusted. The spindle 17 attached to the base or reaction piece 16 extends through this tubular member 56 and beyond the end thereof, and the end 18 is shaped so that it may be turned, thus providing a remote control for positioning the base or reaction piece 16. In this form of burner shown in Figures 5 and 6, there is an intake 15 in the portion 12 of the burner. There is also an annular passage 23 in the body portion 13 of the burner, and passages 21 leading to the mixing chamber. There are also inclined or angular ribs or vanes 26. These features just mentioned are present in the construction shown in Figures 1 and 2 and function rin the same way.

In Fig. 7 there is shown a still further modified form of construction, wherein there are separate inlets for secondary air which is supplied to the burner in front of the mouth piece thereof. Otherwise, the construction shown in Fig. 7 is similar to that shown in Figures 5 and 6. The fuel and air are taken in through the inlet port 60 at the inner end of the burner. There is an annular passage 23 leading to passages 21 which open into the mixing chamber in the burner. There is also a shiftahle reaction plate 16 which is attached to a sleeve 67 extending up through the inner wall of the burner where it is provided with means for shifting the position of the reaction plate 16. There is likewise a shiftable sleeve which is attached to a tubular member 68 extending out through the inner wall of the burner and having a threaded connection CFI p.. LE@

with a bracket and a manually operable member for turning the tubular member for adjusting the sleeve. There is also present in this construction a plurality of vanes 63 mounted on a rod 64. The rod 6l is mounted in bearings and extends through a sleeve 67 and is provided with a remote control 66 therefor whereby it may be turned. This feature of construction is shown and described more in detail in connection with yFigure l. In addition to these features whichk have been described in connect-ion with Figures l to 6, there is a secondary air supply. Surrounding the mouth piece 6l of the burner is a casing having ports 58 controlled by damp-ers 59 which may be independently or collectively operated. The primary air passes in with the fuel through an inlet 60. Secondary air is drawn through these ports and is rdischarged in an annular whirling sheet into the air and fuel mixture leaving the burner mouth. The whirling of the air is accomplished by means of inclined or angular ribs or vanes 5821 similar to those described in connection with Figures l and 2.

It will be appreciated that in the constructions according to the drawings the air and fuel is efficiently mixed prior to ignition by the turbulence set up in the burner chamber due to the violent reversal of direction of iiow of the fuel and air or gas in such chamber. A certain amount of mixing, however, does take place before the chamber is reached by reason of the action of centrifugal force on the fuel and air or gas due to the angled ribs or vanes situated in the ducts between the inlet ports to the burner for the fuel and air or gas and the inlet ports to the burner chamber.

The base or reaction piece in each case preferably has a conical surface against which the air and fuel are projected, such conica-l surface causing a greater reversal of direction for the mixture to be projected outwardly from the burner, in view of the fact that the inlet orifices are situated in the walls of the burner chamber, than would be the case where the base or reaction piece has a plane surface at right angles to the walls of the burner chamber.

l declare that what I claim is l. A burner for pulverulent material having an opening at the outlet end thereof forming the mouth of the burner, a mixing chamber in rear of and opening into said burner mouth, said burner having an inlet passage for the fuel and air mixture adjacent the inlet end of the burner, and an annular passage leading from said inlet passage longitudinally of and around the mixing chamber to a posit-ion in front of the rear of the mixing chamber and thence inwardly in sucstantially a reversed direction into said mixing chamber, whereby a turbulence is set up in the flowing mixture and a complete mixing of the fuel and air effected.

2. A burner for pulverulent material havingan opening at the outlet end thereof forming the mouth of the burner, a mixing chamber in rear of and opening into said burner mouth, sa'd burner having an inlet passage for the fuel and air mixture adjacent the inlet end of the burner, and an annular passage leading from said inlet passage longitudinally of and ar und the mixing chamber to a position in front of the rear of the mixing chamber and thence inwardly in substantially a reversed direction into said mixing chamber, whereby a turbulence is set up in the flowing mixture and a complete mixing of the fuel and air effected, the rear wall of the mixing chamber being` mounted so that it may be adjusted axially of the burner, and means accessible from the outside of the burner for adjusting said wall.

3. A burner for pulverulent material having an opening at the outlet end thereof forming the mouth of the burner, a mixing chamber in rear of and opening into said burner mouth, said burner having an inlet passage for the fuel and air mixture adjacent the inlet end of the burner, and an annular passage leading from said inlet passage longitudinally of and around the mixing chamber to a position in front of the rear of the mixing chamber and thence inwardly in substantially a reversed direction into said mixing chamber, whereby a turbulence is set up in the flowing mixture and a complete mixing of the fuel and air effected, a cylindrical sleeve surrounding the rear portion of the mixing chamber and shiftable axially of the burner for regulating the size of the inlet passage leading into said mixing chamber, and means accessible from the outside of the burner for shifting said sleeve.

el. A burner for pulverulent material having opening the outlet end thereof forming the mouth of the burner, a mixing chamber in rear of and opening into said burner mouth, said burner having an inlet passage for the fuel and air mixture adj acent'the inlet end of the burner, and an annular passage leading from said inlet passage longitudinally of and around the mixing chamber to a position in front of the rear of the mixing chamber and thence inwardly in substantially a reversed direction into said mixing chamber whereby aturbulence is set up in the flowing mixture and a complete mixing of the fuel and air effected, a cylindrical sleeve surrounding the rear portion of the mixing chamber and shiftable axially of the burner for regulating the size of the inlet passages leading into said mixing` chamber, means accessible from the outside of the burner for shifting said Sleeve, the rear wall of the mixing chamber being mounted for adjustment, and means accessible from the outside of the burner for shifting said wall.

5. A burner for pulverulent material having an opening at the outlet end thereof forming 'he mouth of the burner, a mixing chamber in rear of and opening into said burner mouth` said burner having an inlet passage for the fuel and air mixture adjacent the inlet end of the burner and an annular passage leading from said inlet passage longitudinally ci and around the mixing chamber to a position in front oi the rear of the mixing chamber and thence inwardly in substantially a reversed direction into said mixing chamber, whereby a turbulence is set up in the owing mixture and a complete mixing ot the 'fuel and air effected, said annular passage for the fuel and air being provided with ribs disposed at an angle to the longitudinal axis ot the burner whereby the mixture contacting with said ribs will be given a swirling motion prior to the entering oit the mixing chamber.

6. A burner for pulverulent material having an opening at the outlet cnd thereof forming the mouth of the burner, a mixing chamber in rear of and opening into said burner mouth, said burner having an inlet passage for the fuel and air mixture adjacent the inlet end ot the burner, and an annular passage leading 'from said inlet passages longitudinally7 of and around the mixing chamber to a position in front of the rear of the mixing chamber and thence inwardly in substantially a reversed direction into said mixture chamben whereby a turbulence is set up in the flowing mixture and a complete mixing of the fuel and air effected, said annular passage throughout a portion of its length being parallel to the axis of the burner and immediately adjacent the inwardly extending passages leading to the mixing chamber divergent away from said chamber.

7. A burner for pulverulent material having an opening at the outlet end thereof forming the mouth of the burner, a mixing chamber in rear of and opening into said burner mouth, said burner having an inlet passage for the fuel and air mixture adjacent the inlet end of the burner, and an annular passage leading from .said inlet passage longitudinally of and around the mixing chamber to a position in front of the rear of the mixing chamber and thence inwardly in substantially7 a reversed direction into said mixing ch amber, whereby a turbulence is set un in the lowing mixture and a complete mixing of the fuel and air effected, said burner having secondari,7 means for supplying air to the mixture ot fuel and air as it leaves the burner, and means for controlling the secondary supply of air.

8. A burner :tor pulvcrulent material having an opening at the outlet end thereof forming the mouth of the burner, a mixing chamber in rear of and opening into said burner mouth, said burner having an inlet passage for the fuel and air mixture adjacent the inlet end of the burner, and an annular passage leading from said inlet passage longitudinally or' and around the mixing chamber to a position in front of the rear of the mixing chamber and thence inwardly in substantially a reversed direction into said mixing chamber, whereby a turbulence is set up in the flowing mixture and a complete mixing of the fuel and air effected, anddisplaceable vanes mount-ed in the mouth of said burner and means accessible from the outside of the burner 'for shifting the position of said vanes.

In witness whereof, I have hereunto signed my name this 12th day of March, 1929.

ALFRED VILLIAM BENNIS.

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